A moderator explained to me in a separate thread: Microsoft believe that the lack of apps for WP8.1 is the reason why it never took off. They've produced a couple of software tools which help developers port their Android and iOS apps over to W10M.

However, in order to make this porting viable they've largely abandoned the WP8.1 design language and made the W10M user interface much more like iOS and Android, including common controls like the hamburger menu.

Personally I think they are wrong about why WP8.1 never really got a toehold in the market, and I don't believe this approach will boost the available apps by much.

In particular, now that W10M is an Android look-alike the obvious reaction from a user would be to stop messing around and just use the real thing - Android!

A moderator explained to me in a separate thread: Microsoft believe that the lack of apps for WP8.1 is the reason why it never took off.

Be careful not to put words into a moderator's mouth ;-)

I didn't say what MS believes to be the reasons for WP so far failing to really catch on. Whatever their conclusions on that issue are, I'm sure they are a lot more comprehensive than a single sentence placing all the blame on the lack of apps. There will inevitably be many reasons. Not just one.

I'd be surprised if MS actually believes/hopes the ability to easily port iOS/Android apps will turn WM's fortunes around. You don't believe that. I don't believe that. I don't think MS believes that either. IMHO those tools represent little more than a life jacket. They'll help prevent WM from drowning, but they won't get WM out of the water.